Safety central shaft extension and contraction control structure of self-opening/closing umbrella

ABSTRACT

A safety central shaft extension and contraction control structure is mounted in a handle of a self-opening/closing umbrella and includes a main body mounted to a first shaft segment of the central shaft. Mounted to a lower portion of the main body are an operation plate and a pawl plate, which are in engagement with each other, and a reversal prevention wheel having a toothed surface. A safety rope is wrapped around the reversal prevention wheel and has an end attached to a crown of the umbrella. When errors occur in the course of compression of the central shaft in closing the umbrella, the central shaft that is being compressed can be held in position, so that instantaneous spring back of the central shaft caused by an umbrella opening spring that is in a compressed condition can be prevented to ensure safety of operation and control of the self-opening/closing umbrella.

(a) TECHNICAL FIELD OF THE INVENTION

The present invention generally relates to a self-opening/closing umbrella, and more particularly to a centrals shaft control structure of a self-opening/closing umbrella.

(b) DESCRIPTION OF THE PRIOR ART

A conventional self-opening/closing umbrella is shown in FIGS. 1-3. The known umbrella comprises a handle 1 inside which an operation unit 2 is provided, a central shaft unit 3 inside which an umbrella opening spring 6 is received, and a runner 4 coupled to ribs 7 and comprising a pull rope 51 wrapping therearound and having an end fixed to a crown 41 and an opposite end fixed to a bullet-head member 5. The operation unit 2 comprises a hollow body inside which components including a control ring 201, a control bar 202, and a pushbutton 203 are received. The control bar 202 is pivoted to a lower portion of one side of the bottom of the control ring 201. The pushbutton 203 is received in an opening formed in a side wall of the handle 1 and is exposed for controlling the extension and contraction of the central shaft unit 3.

As shown in FIG. 1, the control ring 201 comprises a small spring 2011 externally set at one side thereof. The control ring 201 forms therein a projection bar 2012 at a location corresponding to the small spring 2011 to engage and retain the runner 4 for keeping the umbrella in a collapsed condition. Further, the control bar 202 is coupled by a pivot pin 2021 to the bottom of the control ring 201 at a location close to the pushbutton and comprises a torsion spring 2022 that normally maintains the control bar 202 in a horizontal condition. When the umbrella is in a compressed and ready-to-use condition, the runner 4 is retained in position by the projection bar 2012 of the control ring 201 and the control bar 202 is pushed downward by a second central shaft segment 32 of the central shaft unit 3 to become inclined. The bullet-head member 5 is pushed by an inner tube 34 received in a third central shaft segment 33 and biased by a spring plate 311 to engage a retention hole defined in a first central shaft segment 31 of the central shaft unit 3. As shown in FIG. 2, when the pushbutton 203 is depressed for the first time, the control ring 201 is pushed inward to have the projection bar 2012 disengaging from the runner 4 and under the action of the umbrella opening spring 6 received inside the central shaft unit 3, opening operation of the umbrella is automatically carried out and under this condition, the control bar 202 returns to the normal horizontal condition and contacts the bullet-head member 5.

To close the umbrella, the pushbutton 203 is pressed down again, and the control bar 202 pushes and causes the bullet-head member 5 to disengage from the first central shaft segment 31, allowing the runner 4 to be movable. Under the action of the umbrella closing springs 71 provided on the ribs 7, the ribs 7 and the umbrella canopy are collapsed and the runner 4 is moved downward (see FIG. 3). Afterward, the top end of the umbrella can be forcibly pushed to compress the central shaft unit 3 toward the handle 1, thereby completing the closing of the umbrella as shown in FIG. 1.

However, a problem of the above mentioned self-opening/closing umbrella occurs in the course of compressing and closing of the umbrella. To close the umbrella requires compression of the umbrella opening spring 6 received inside the central shaft unit 3. Since the umbrella opening spring 6 is of quite a strength and spring force, a user must apply a great force with his or her hand to compress the umbrella. If the application of force is in error, the compressed umbrella opening spring 6 will spring the central shaft unit 3 back with a great force. This often hurts the hands or other portions of the body of the user. Thus, the closing operation of the known self-opening/closing umbrella is dangerous and improvement in this respect is needed.

SUMMARY OF THE INVENTION

The present invention provides a safety control structure for controlling extension and contraction of a central shaft of a collapsible umbrella in a safe manner and the control structure according the present invention is generally designated at 2 as shown in FIG. 4. The control structure 2 of the present invention comprises the following constituent components including a main body 20, a collar 21, an operation plate 22, a pawl plate 23, and a reversal prevention wheel 24. A lining tube 35 that forms an opening 351 in a side thereof is received and fixed in a lower end of a first shaft segment 31 of a central shaft unit 3 of the umbrella, which will be further described and is received and fixed inside the main body 20. The first shaft segment 31 also forms a hole 311 in a side thereof close to the lower end and also forms an elongate groove 312, in which an opening 313 is formed at an upper end thereof, in an adjacent side of the first shaft segment 31. The collar 21 receives therein a spring 28 that is fit over the first shaft segment 31. The operation plate 22 and the pawl plate 23 are set in engagement with each other and are mounted to the main body 20 to be located below one side of the collar 21. The pawl plate 23 is biased at one side thereof by a spring 29. The reversal prevention wheel 24 is mounted to the main body 20 and located below the pawl plate 23 and has one side forming a toothed surface 241 that forms thereon a plurality of ratchet teeth that are inclined in the same direction. The reversal prevention wheel 24 receives therein a coil spring 242. A safety rope 25 is wrapped around the reversal prevention wheel 24 and has an end fixed to the reversal prevention wheel 24 and an opposite end extending along the elongate groove 312 of the first shaft segment 31 and extending through the opening 313 into the interior space of the central shaft unit 3 to attach upward to a crown 41 of the umbrella. During the closing of the umbrella, when the operation of compressing the central shaft of the umbrella is in error, with the engagement that is instantaneously formed between the pawl plate 23 and the reversal prevention wheel 24 and the pulling action provided by the safety rope 25, the central shaft unit 3 that is in the process of being compressed is kept in position thereby preventing abrupt extension of the central shaft unit 3 caused by the action of an umbrella opening spring 6. By using this kind of arrangement of safety that directly works on the central shaft of an umbrella, absolute safety for the use and control of umbrella opening can be ensured.

The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.

Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-3 are schematic views illustrating structural arrangement and operation of a conventional self-opening/closing umbrella.

FIG. 4 is an exploded view of a safety central shaft extension and contraction control structure according to an embodiment of the present invention.

FIGS. 5-7 are schematic views illustrating structural arrangement and operation of the safety central shaft extension and contraction control structure according to the present invention.

FIGS. 8 and 9 are schematic views showing a modification of the safety central shaft extension and contraction control structure according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

The present invention provides a safety control structure for controlling extension and contraction of a central shaft of a collapsible umbrella in a safe manner and the control structure according the present invention is generally designated at 2 as shown in FIG. 4. The control structure 2 of the present invention comprises the following constituent components including a main body 20, a collar 21, an operation plate 22, a pawl plate 23, and a reversal prevention wheel 24. A lining tube 35 that forms an opening 351 in a side thereof is received and fixed in a lower end of a first shaft segment 31 of a central shaft unit 3 of the umbrella, which will be further described and is received and fixed inside the main body 20. The first shaft segment 31 also forms a hole 311 in a side thereof close to the lower end and also forms an elongate groove 312, in which an opening 313 is formed at an upper end thereof, in an adjacent side of the first shaft segment 31. The collar 21 receives therein a spring 28 that is fit over the first shaft segment 31. The operation plate 22 and the pawl plate 23 are set in engagement with each other and are mounted to the main body 20 to be located below one side of the collar 21. The pawl plate 23 is biased at one side thereof by a spring 29. The reversal prevention wheel 24 is mounted to the main body 20 and located below the pawl plate 23 and has one side forming a toothed surface 241 that forms thereon a plurality of ratchet teeth that are inclined in the same direction. The reversal prevention wheel 24 receives therein a coil spring 242. A safety rope 25 is wrapped around the reversal prevention wheel 24 and has an end fixed to the reversal prevention wheel 24 and an opposite end extending along the elongate groove 312 of the first shaft segment 31 and extending through the opening 313 into the interior space of the central shaft unit 3 to attach upward to a crown 41 of the umbrella. During the closing of the umbrella, when the operation of compressing the central shaft of the umbrella is in error, with the engagement that is instantaneously formed between the pawl plate 23 and the reversal prevention wheel 24 and the pulling action provided by the safety rope 25, the central shaft unit 3 that is in the process of being compressed is kept in position thereby preventing abrupt extension of the central shaft unit 3 caused by the action of an umbrella opening spring 6 (which will be further described hereinafter). By using this kind of arrangement of safety that directly works on the central shaft of an umbrella, absolute safety for the use and control of umbrella opening can be ensured.

Referring to FIG. 5, the present invention provides a safety central shaft extension and contraction control structure of a self-opening/closing umbrella, which will be explained with reference to an example of a three-fold umbrella, generally comprising the following constituent components including a handle 1, a central shaft unit 3, a runner 4, a bullet-head member 5, an umbrella opening spring 6, and ribs 7. The handle 1 is provided with a pushbutton 11, which comprises a control ring 26 and a control bar 27. The central shaft unit 30 is composed of a first shaft segment 31, a second shaft segment 32, and a third shaft segment 33, which are telescopically fit to each other. The third shaft segment 33 has an upper end to which a crown 41 is fixed and a lower end, which forms a retention hole 331 in a side thereof. The crown 41 has a lower end to which an inner tube 34 is fixed. The umbrella opening spring 60 is arranged between the first shaft segment 31 and the inner tube 34. The bullet-head member 50 is set below the inner tube 34 and has an upper end to which a pull rope 51 is attached so that the pull rope 51 extends upward through the inner tube 34 and wraps around a pulley set inside the crown 41 and further projects outwards to wrap around a pulley set inside the runner 4 to have a distal end thereof attached to the crown 41. The control structure according to the present invention, broadly designated at 2, is received in the handle 1 and is fixed to a lower end of the first shaft segment 31.

FIG. 5 shows the structural arrangement of the self-opening/closing umbrella according to the present invention in a compressed and closed condition, in which the retention hole 331 of third shaft segment 33 and a projection block 261 formed on the control ring 26 engage each other so as to retain the central shaft unit 3 in position. At the same time, the control bar 27 is pushed downward by the third shaft segment 33 and becomes inclined. The bullet-head member 50, which is coupled to the runner 4 with the pull rope 51, is pushed downward by the inner tube 34 and is biased by a spring plate 36 arranged inside a lining tube 35, which is received in the first shaft segment 31 and constitutes a part of the control structure of the present invention, to engage and thus be retained by the opening 351 of the lining tube 35. Meanwhile, the second shaft segment 32 pushes the collar 21 downward to have a top flange of the collar 21 contacting an upper end of the operation plate 22 and causing rotation of the operation plate 22 to move the upper end thereof rightwards as shown in the drawing. The operation plate 22 in turn has a lower end thereof, which is in engagement with an upper end of the pawl plate 23, contacts and rotates the pawl plate 23 so as to move the upper end of the pawl plate 23 leftwards, by which a lower end of the pawl plate 23 is moved rightward and thus disengaging from the toothed surface 241 of the reversal prevention wheel 24. Under this condition, the coil spring 242 received in the reversal prevention wheel 24 is in a completely released condition and the safety rope 25 is wound around the reversal prevention wheel 24.

Referring to FIG. 6, to open the umbrella, the pushbutton 11 is depressed to move the control ring 26 inward thereby disengaging the projection block 261 from the retention hole 331 of the third shaft segment 33. Under the action of the umbrella opening spring 6 arranged inside the central shaft unit 3, the central shaft unit 3 is fully extended and the runner 4 that moves upward with the central shaft unit 3 forcibly expands all the ribs 7 to complete the operation of opening umbrella. Under this condition, the control bar 27 returns to the horizontal condition and is in contact with the bullet-head member 5. The safety rope 25 of which the upper end is attached to the crown 41 is extended upward with the upward movement of the crown 41 and causes counterclockwise rotation of the reversal prevention wheel 24, making the coil spring 242 to wind up inside the reversal prevention wheel 24.

Referring to FIG. 7, to close the umbrella, the pushbutton 11 is depressed again and by doing so, the control bar 27 pushes the bullet-head member 5 in such a way to disengage the bullet-head member 5 from the opening 351 of the lining tube 35. Due to the action of an umbrella closing spring 71 provided in each rib 7, the rib 7 is collapsed and drives the runner 4 downward. The pull rope 51 moves the bullet-head member 5 upward to the lower end of the inner tube 34. Under this condition, the collar 21 is no longer held in position by the second shaft segment 32 and is biased upward by the spring 28 to return to the original position. The spring 29 arranged at one side of the pawl plate 23 drives the upper end of the pawl plate 23 to rotate rightward, causing the lower end thereof to rotate leftward and resume in engagement with the toothed surface 241 of the reversal prevention wheel 24.

Referring to FIGS. 5 and 7, the final step of closing umbrella is to compress the central shaft unit 3 of the umbrella. When the central shaft unit 3 is acted upon and thus compressed by an external force, the safety rope 25 follows the inward contraction of the central shaft unit 3 to get released. Under this condition, the reversal prevention wheel 24 is acted by the returning spring force of the coil spring 242 to rotate in the clockwise direction. Due to the ratchet teeth of the toothed surface 241 of the reversal prevention wheel 24 being of a single side inclined configuration, when the reversal prevention wheel 24 rotates clockwise, the toothed surface 241 is not constrained by the pawl plate 23, but when the compression force is removed, the spring force induced by the umbrella opening spring 6 inside the central shaft unit 3 tends to extend the central shaft unit 3, but since the safety rope 25 mounted to the reversal prevention wheel 24 has an end fixed to the crown 41, the extension force is transmitted through the safety rope 25, attempting to cause counterclockwise rotation of the reversal prevention wheel 24; this makes the pawl plate 23 engaging and retaining the single-side-inclined ratchet teeth of the toothed surface 241 of the reversal prevention wheel 24 to prevent the reversal prevention wheel 23 from counterclockwise rotation and directly holding the third shaft segment 33 in position to immediately stop undesired and abrupt extension of the central shaft unit 3. Thus, when the umbrella compression operation is mistakenly in error and slips up, the reversal prevention wheel 24 is held in position by the pawl plate 23 and directly holds the central shaft unit 3 in position to prevent the central shaft unit 3 from being acted upon by the compressed umbrella opening spring 6 to induce instantaneous spring back or undesired extension, whereby operation safety of the self-opening/closing umbrella can be ensured.

FIGS. 8 and 9 show a modification of the present invention, wherein two pushbuttons 11 are provided on an umbrella handle 1 respectively for umbrella opening and umbrella closing. Further, two control rings 26 are arranged inside the handle 1 to correspond to and cooperate with the two pushbuttons 11 for carrying the respective operations. This arrangement provides the same result as that of the single pushbutton arrangement.

While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. 

1. A safety central shaft extension and contraction control structure for use in a self-opening/closing umbrella, the safety control structure comprising a main body, a collar, an operation plate, a pawl plate, and a reversal prevention wheel, the safety control structure being adapted to be received in a handle of the umbrella, the central shaft of the umbrella comprising a first shaft segment having a lower end that receives and fixes a lining tube that forms an opening in a side thereof and is received and fixed inside the main body, the collar receiving therein a spring that is fit over the first shaft segment, the operation plate and the pawl plate being set in engagement with each other and mounted to the main body to be located below one side of the collar, the pawl plate being is biased at one side thereof by a spring, the reversal prevention wheel being mounted to the main body and located below the pawl plate and having one side forming a toothed surface that forms thereon a plurality of ratchet teeth that are inclined in the same direction, the reversal prevention wheel receiving and holding therein a coil spring, a safety rope being wrapped around the reversal prevention wheel and having an end fixed to the reversal prevention wheel and an opposite end attached to a crown of the umbrella, whereby when an operation of compressing the central shaft of the umbrella is in error in closing the umbrella, with the pawl plate and the reversal prevention wheel instantaneously forming engagement therebetween and a pulling action realized by the safety rope, the central shaft that is in the process of being compressed is kept in position thereby preventing abrupt extension of the central shaft caused by the action of an umbrella opening spring of the umbrella.
 2. The safety central shaft extension and contraction control structure according to claim 1, wherein the first shaft segment forms a hole in a side thereof close to the lower end and also forms an elongate groove, in which an opening is formed at an upper end thereof, in an adjacent side of the first shaft segment and wherein the safety rope extends along the elongate groove of the first shaft segment and extends through the opening into interior space of the central shaft to attach upward to the crown of the umbrella. 